Performance problems

Hi, We have the same database system on multiple machines at hundreds of customer sites. It is based on Online 5.01. At several sites, a severe performance problem has developed. At some sites, this slowed down SELECTs. At some - UPDATEs involving a specific trigger became very slow (and this was at the trigger condition evaluation stage, which was false, so that the trigger action was actually never activated). The database tables were not fragmented, no indexes were missing or corrupted at these customer sites. tbcheck -cIn and -cDn revealed no problems in regular tables or in sys tables. Dropping and re-creating the indexes did not help. At some other customer sites, with much larger databases of the same structure and same application - there were no complaints at all The only thing that solved this strange problem was dbexporting, dropping the database and then dbimporting it back. This increased the transaction speed 10-15 times. Any guess what's going on? Maybe some obscure sys tables corruption that dbimport re-builds? Doron Rippel doron@usa.net